The invention discloses a fine tuning system and method of an nonballast track slab in the technical field of automatic control. The system comprises a total station, an industrial personal computer (IPC), a programmable logic controller (PLC), a servo motor driver and a servo motor fine tuner which are connected in sequence. The method comprises the following steps that: the total station measures the current direction and offset of the nonballast track slab and sends the current direction and offset to the IPC; the IPC recognizes the pose of the nonballast track slab and calculates the tuned quantity of the nonballast track slab and sends the tuned quantity to the PLC; the PLC generates a pulse signal and sends the pulse signal to the servo motor driver; the servo motor driver generatesa control signal and sends the control signal to the servo motor fine tuner; and the servo motor fine tuner drives a fine tuner nut sleeve to rotate and controls the revolutions of the rotation. The invention realizes that the efficiency and the precision for paving track slabs are increased.